The present application relates to the field of X-ray imaging. It finds particular relevance to projection and computed tomography (CT) imaging systems such as utilized in medical, security, industrial and/or other applications. It also relates to other forms of X-ray imaging systems where dynamically adjusting X-ray acquisition parameters may be useful.
Today, CT and other X-ray imaging modalities (e.g., mammography systems, projection radiography systems, scanning line systems, etc.) are useful to provide information, or images, of interior aspects of an object under examination. Generally, the object is exposed to X-ray radiation comprising X-ray photons, and an image(s) is formed based upon the radiation absorbed and/or attenuated by interior aspects of the object, or rather an amount of photons that is able to pass through the object. Generally, highly dense aspects of the object absorb and/or attenuate more radiation than less dense aspects, and thus an aspect having a higher density, such as a bone or metal, for example, may be apparent when surrounded by less dense aspects, such as muscle or clothing.
To construct an image, X-ray radiation is emitted and information is acquired according to X-ray acquisition parameters that specify, among other things, an X-ray tube current and/or voltage, beam filtration, data filtration, etc., for example. The information acquired from the X-ray examination is then reconstructed or assembled to form an image which a user, such as a radiologist or security personnel, can view.
Presently, X-ray tube current may be dynamically adjusted during an examination as a function of the view angle in CT (e.g., which may be known to those skilled in the art as an ‘auto mA’ functionality) and/or as a function of an auto-exposure feature in a projection acquisition. However, other X-ray acquisition parameters are not known to be adjusted during the examination. This is in contrast to ultrasound imaging, where imaging parameters may be dynamically adjusted by a clinician during the examination as a function of the visual representation of the object to improve the representation of a desired aspect of the object. For example, during an ultrasound examination, a clinician may alter the frequency of the ultrasound waves and/or make other adjustments that improve the image quality or usefulness of the image with respect to an aspect of the object that is of particular interest.